NAME

maildropex - maildrop filtering language examples

SYNOPSIS

$HOME/.mailfilter, $HOME/.mailfilters/*

DESCRIPTION

If $HOME/.mailfilter exists, filtering instructions in this file will
be carried out prior to delivering the message. The filtering
instructions may instruct maildrop to discard the message, save the
message in a different mailbox, or forward the message to another
address. If $HOME/.mailfilter does not exist, or does not provide
explicit delivery instructions, maildrop delivers the message to the
user’s system mailbox.
The files in $HOME/.mailfilters are used when maildrop is invoked in
embedded mode.

EXAMPLES

Take all mail that’s sent to the ’auto’ mailing list, and save it in
Mail/auto. The ’auto’ mailing list software adds a "Delivered-To:
auto@domain.com" header to all messages:
if (/^Delivered-To: *auto@domain\.com$/)
to Mail/auto
After the to command delivers the message, maildrop automatically stops
filtering and terminates without executing the subsequent instructions
in the filterfile.
Take all mail from <boss@domain.com> about the current project status,
save it in Mail/project, then forward a copy to John:
if (/^From: *boss@domain\.com/ \
&& /^Subject:.*[:wbreak:]project status[:wbreak:]/)
{
cc "!john"
to Mail/project
}
Note that it is necessary to use a backslash in order to continue the
if statement on the next line.
Keep copies of the last 50 messages that you received in the maildir
directory ’backup’. NOTE: ’backup’ must be a maildir directory, not a
mailbox. You can create a maildir using the maildirmake command.
cc backup
‘cd backup/new && rm -f dummy \‘ls -t | sed -e 1,50d\‘‘
Put this at the beginning of your filter file, before any other
filtering instructions. This is a good idea to have when you are
learning maildrop. If you make a mistake and accidentally delete a
message, you can recover it from the backup/new subdirectory.
Save messages that are at least 100 lines long (approximately) into
Mail/IN.Large::
if ( $LINES > 100 )
to Mail/IN.Large
Send messages from the auto mailing list to the program ’archive’,
using a lock file to make sure that only one instance of the archive
program will be running at the same time:
if (/^Delivered-To: *auto@domain\.com$/)
dotlock "auto.lock" {
to "|archive"
}
Check if the Message-ID: header in the message is identical to the same
header that was recently seen. Discard the message if it is, otherwise
continue to filter the message:
‘reformail -D 8000 duplicate.cache‘
if ( $RETURNCODE == 0 )
exit
The reformail command maintains a list of recently seen Message-IDs in
the file duplicate.cache.
Here’s a more complicated example. This fragment is intended to go
right after the message has been filtered according to your regular
rules, and just before the message should be saved in your mailbox:
cc $DEFAULT
xfilter "reformail -r -t"
/^To:.*/
getaddr($MATCH) =~ /^.*/;
MATCH=tolower($MATCH)
flock "vacation.lock" {
‘fgrep -iqx "$MATCH" vacation.lst 2>/dev/null || { \
echo "$MATCH" >>vacation.lst ; \
exit 1 ; \
} ‘
}
if ( $RETURNCODE == 0 )
exit
to "| ( cat - ; echo ’’; cat vacation.msg) | $SENDMAIL"
This code maintains a list of everyone who sent you mail in the file
called vacation.lst. When a message is received from anyone that is
not already on the list, the address is added to the list, and the
contents of the file vacation.msg are mailed back to the sender. This
is intended to reply notify people that you will not be answering mail
for a short period of time.
The first statement saves the original message in your regular mailbox.
Then, xfilter< is used to generate an autoreply header to the sender.
The To: header in the autoreply - which was the sender of the original
message - is extracted, and the getaddr function is used to strip the
person’s name, leaving the address only. The file vacation.lst is
checked, using a lock file to guarantee atomic access and update
(overkill, probably). Note that the backslashes are required.
If the address is already in the file, maildrop exits, otherwise the
contents of vacation.msg are appended to the autoreply header, and
mailed out.
Note: An easier to make a vacation script is with mailbot(1).
Here’s a version of the vacation script that uses a GDBM database file
instead. The difference between this script and the previous script is
that the previous script will send a vacation message to a given E-mail
address only once. The following script will store the time that the
vacation message was sent in the GDBM file. If it’s been at least a
week since the vacation message has been sent to the given address,
another vacation message will be sent.
Even though a GDBM database file is used, locking is still necessary
because the GDBM library does not allow more than one process to open
the same database file for writing:
cc $DEFAULT
xfilter "reformail -r -t"
/^To:.*/
getaddr($MATCH) =~ /^.*/;
MATCH=tolower($MATCH)
flock "vacation.lock" {
current_time=time;
if (gdbmopen("vacation.dat", "C") == 0)
{
if ( (prev_time=gdbmfetch($MATCH)) ne "" && \
$prev_time >= $current_time - 60 * 60 * 24 * 7)
{
exit
}
gdbmstore($MATCH, $current_time)
gdbmclose
}
}
to "| ( cat - ; echo ’’; cat vacation.msg) | $SENDMAIL"
This script requires that maildrop must be compiled with GDBM support
enabled, which is done by default if GDBM libraries are present.
After you return from vacation, you can use a simple Perl script to
obtain a list of everyone who sent you mail (of course, that can also
be determined by examining your mailbox).